Spring tensioning device for the actuation of circuit breakers



Nov. 15, 1960 Filed Jan. 10, 1955 A. LATOUR SPRING TENSIONING DEVICE FORTHE ACTUATION OF CIRCUIT BREAKERS FIG. I.

4 Sheets-Sheet l INVENTOR l ANDRE LATOUR.

BY MM M ATTORNEY Nov. 15, 1960 A. LATOUR SPRING TENSIONING DEVICE FORTHE ACTUATION OF CIRCUIT BREAKERS 4 Sheets-Sheet 2 Filed Jan 10, 1955 ma 25%? M .b w m INVENTQR ANDRE LATOUR. BY

ATTORNEY NOV. 15, 1960 LATQUR 2,960,186

SPRING TENSIONING DEVICE FOR THE ACTUATION OF CIRCUIT BREAKERS FiledJan. 10, 1955 4 Sheets-Sheet 3 FIG. 4.

INV ENTOR ANDRE LATOUR.

M 44mm ATTORNEY Nov. 15, 1960 LATQUR 2,960,186

SPRING TENSIONING DEVICE FOR THE ACTUATION OF CIRCUIT BREAKERS FiledJan. 10, 1955 4 Sheets-Sheet 4 I39 141 I40 FIG. 5.

J l6l I48 -:-l66 1 M82 FIG 8 i l |9o- I89 INVENTOR I ANDRE LATOUR.

ATTORNEY Unite SPRING TENSIONING DEVICE FOR THE ACTUA- TIGN OF CRUUITBREAKERS Andre Latonr, Grenoble, France, assignor to EtablissementsMerlin & Gerin, Grenoble, France Filed Ian. 10, 1955, Ser. No. 480,951

Claims priority, application France Jan. 28, 1954 3 Claims. (Cl. 185-40)ment of an energy source of moderate capacity and of apparatus ofmoderate size, small space requirement and little cost of constructionand attendance.

With this object in view, the invention provides for a device by meansof which power of low magnitude is intermittently withdrawn from thesource of energy, a device which makes it possible to tension the springstep by step and which is characterized by small space requirement,reduced cost and by the simplicity of the means employed as well as bythe facility with which the energy withdrawn at each moment may beregulated.

In the device according to the invention, the spring is tensionedstepwise, in intermittent action at a predetermined pulsating flow rateof energy supply, under the action of a tensioning member operated by apulse rcsponsive driving mechanism to which energy pulses controlled bya pulse controller are supplied pulsatingly.

In further development of the invention, these energy pulses areintermittently supplied to the spring tensioning member through adriving mechanism which includes a motor having a reciprocatory, movablemember and motion transmitting mechanism which connects the movablemember with the spring tensioning member. This motion transmittingmechanism will convert each cycle of the motor movement into a fractionof the total stroke of the spring tensioning member or a fraction of thespring expansion or compression whichever the case may be when thespring is tensioned. The supply of energy from its source to the pulseresponsive driving mechanism is under the control of a pulse controllerwhich may intermittently connect and disconnect the source of energy tothe driving mechanism or may generate directly or indirectly energypulses to be supplied to the driving mechanism or the motor thereof.Owing to this pulse controller, the pulsating flow rate of energy, bymeans of which the spring is to be tensioned, may readily bepredetermined through proper choice of the characteristics of thepulses, viz. their amplitude, duration, the intervals between the pulsesand other characteristics.

In the embodiments hereinafter exemplified, I make use, as the source ofintermittent mechanical energy, of an electromagnet pulsatinglyenergized and operatively connected to the spring to be tensioned.

To this purpose, the electromagnet, by means of a spring tensionedrocking lever and intermediary pulse responsive apparatus, will operatethe spring tensioning member and will thus tension the spring, step bystep,

Sttes Patent in accordance with the repetition rate of the energypulses. The intermediary apparatus may be of the type which includes astep measuring gear by means of which the spring tensioning member isoperated and the spring tensioned in steps of constant, definite length,such as by a ratchet gear, toothed rack or ratchet wheel. The intermediary apparatus may also be of the type which does not produce orrequire actuating steps of a constant, definite length but may operateor advance the spring tensioning member in steps of indeterminateamplitude. To this purpose, an incompressible fluid transmission orhydraulic drive, or clutches of the unidirectional wedge-grip type, orany other pulse responsive apparatus may be employed.

The pulsating or rhythmic energizing of the electromagnet may beeffected by any conventional or convenient device, in this specificationreferred to as pulse controller which may also be specific apparatusdeveloped in accordance with the invention as will be set forthhereinafter, a device or apparatus by means of which pulses ofmechanical or electrical energy may be derived from a source ofpermanent energy.

The pulse controller may thus be a relay, a clockwork, or a motor,periodically or pulsatingly closing and opening a switch in theenergizing circuit of the electromagnet, or the pulse controller may bean electric pulse generator energizing the coil of the electromagnet byrhythmic pulses, or it may be any apparatus by means of which rhythmicpulses are produced for a pulsating, step by step operation of thespring tensioning member.

The pulse controller, in accordance with a development of the invention,may also include or comprise control or switching means for the closingand opening of the supply circuit to the eleetromagnet or otherreciprocatory motor, control or switching means which are 0p- .erated orcontrolled by the reciprocatory motion of the electromagnet or other.motor or of any organ reciprocated or rocked thereby.

Further features and objects of my invention will became apparent as thenow ensuing specific description of the invention proceeds in which theinvention will be described with reference to the accompanying drawingswhich form part of this specification and which by way of exampleillusrate various embodiments of my invention.

These drawings, however, are to be understood explicative .of myinvention but not limitative of its scope. Other embodimentsincorporating the principle underlying my invention are feasible withoutdeparting from the spirit and ambit of my appended claims.

Inthe drawings:

Fig. 1 is a schematical elevational view, partly in sec- .tion, of adeviceof the invention in which the spring is from the electromagnetthrough the intermediary of a hydraulic transmission;

Fig. 4 is a schematical elevational view, partly in section,illustrating as an example the application .of the spring tensioningmember to an oil circuit breaker for the closing of the same;

Fig. 5 is a schematicalelevational view of an embodiment in which thespring is tensioned, or mechanical energy accumulated, from theelectromagnet through the intermediary of clutches for unidirectionalwedge grip;

Fig. 6 is a plan view of the embodiment of Fig. 5

Fig. 7 is an elevational view partly in section, along line 7-7 of Fig.6; and

Fig. 8 is a diagram illustrating schematically the application of theoperating shaft of the embodiment of Figs. and 6 to the actuation of acircuit breaker.

In the embodiment of Fig. l, the spring to be tensioned by the device ofthe invention is designated by 11. 12 is the spring tensioning member,in the embodiment illustrated a bar, provided with a toothed rack 13 andguided by guide rollers 14, 15. The movable contact of a circuit breakeris connected to bar 12 as will be described in detail hereinafter withreference to Fig. 4.

21 generally designates the electromagnet with its coil 22, theferromagnetic frame or housing 23 or flux return path, and the movablemagnetic core or plunger 24. The

coil 22 of the electro-magnet 21 is energized from a network 28 underthe control of a pulse controller generally designated by 30. This pulsecontroller may be of any of the types hereinabove referred to, and isindicated diagrammatically in Figs. 2 and 3 by the dash-line square 30,and in the embodiment of Fig. 1 by a contact wheel 31 driven by aconventional motor 32, in the instance illustrated by an electromotor.The fingers 33 of contact Wheel 31, when motor 32 is energized andrunning, close and open, intermittently and rhythmically, the contact 34in the energizing circuit of the electromagnet.

Stationary set screws 35, 36 and co-operating abutments 37, 38, providedat the plunger, limit the drop of plunger 24 when the coil of theelectromagnet is de-energized and thus determine the amplitude of thestroke of the electromagnet.

Plunger 24, by means of link 41, is coupled to a rocking lever 42pivotal about pivot 43 and biased by spring 44 so as, when coil 22 isde-energized, to pull and return plunger 24 into the rest position shownin Figs. 1 to 3. Rocking lever 42 carries at its end, pivotal about pin49, the driving pawl 45 which, in the embodiment of Fig. l, engages theteeth of rack 13. Spring 46 holds the pawl 45 resilently in engagementwith these teeth.

A holding pawl 47, pivotal about pin 50 and held in engagement with theteeth of rack 13 by a spring 48, blocks the return of the springtensioning bar 12 after each advance step caused through pawl 45 andguided by the guide rollers 14, 15.

A stop 52 provided at bar 12 opens, on the end of the stroke of thespring tensioning bar 12, when spring 11 is fully tensioned, the strokelimiting switch 53 and stops through the opening of line 54, 55 theenergy supply to the pulse controller 30 and the electromagnet 21.

When the tensioned spring is to be released, the pawls 45 and 47 will bepivoted out of engagement with rack 13 by means of proper releasemechanism as is, per se, well known in the art. This mechanism, sincenot forming part of the invention, is merely diagrammatically indicatedby the lever system 62 operable by hand, knob 63, or by remote control64.

Fig. 2 illustrates a modification of the embodiment of Fig. 1 in whichthe tensioning of the spring is elfected through the rotational motionof a ratchet wheel 65. At each energy pulse, supplied from the pulsecontroller 30 to the electromagnet, the plunger 24, through theintermediary of rocking lever 42 and the driving pawl 45, imparts to theratchet wheel 65, as indicated by the arrow G, a counter-clockwisemotion which rotates the wheel one tooth, the wheel being held by theholding pawl 47 against any return movement. A lever 66 secured to thewheel 65 imparts to rod 67 a movement, guided by the bearings 68, 69, inthe sense of arrow H, a movement which by means of the flange ring 71seated upon rod 67 tensions the spring 70 carried by rod 67.

Spring 70 may be released by any conventional release mechanism similarto that diagrammatically shown in Fig. 1, here merely indicated byarrows pointing to 62. By means of such mechanism, when spring 70 is tobe released, pawls 45 and 47 will be pivoted by hand or by remotecontrol and against the action of springs 46 and 48 out of engagementwith the ratchet wheel 65.

Fig. 3 shows an embodiment of the invention in which the steps of thespring tensioning member are not necessarily constant and definite as inthe foregoing examples. In this embodiment, the spring 72 is tensionedby the intermediary of a hydraulic mechanism, comprising the pump 75,the hydraulic jack and the reservoir 87 or other source ofincompressible fluid, respectively connected by conduits 78, 86 and 88controlled by non-return valves 79, 83 and 89. These non-return valves,since well known in the art, are not shown here in detail but are merelyindicated schematically by balls.

With each energy pulse supplied to the electromagnet 21, the rockinglever 42 will impart to the piston rod 76 and the piston 77 of thehydraulic pump 75 a downward stroke which, while opening the non-returnvalve 79, will drive the incompressible fluid, preferably oil, containedwithin cylinder 75, through the conduit 78 into the space of thehydraulic jack 80.

Under the pressure of the liquid delivered into the space of thehydraulic jack 80, piston 81 will move downwards and thus will executeone step and will, by means of its rod 82, tension the spring 72.

At the end of each pulse, lever 42 and piston 77, under the action ofspring 44, will return into their initial rest position. On the returnmovement of its piston 77, cylinder 75 is refilled with oil drawn fromthe reservoir 87 through conduit 88, the non-return valve 89 openingunder the diminished pressure within the space 75. The cycle is repeatedwith each pulse, until, after a predetermined number of pulses, spring72 is completely tensioned and the energizing circuit is opened, forinstance by a stop 53 provided upon the piston rod 82 and a strokelimiting switch 53, as will be described hereinafter in detail.

The return of piston 81 after each advance under the tension of spring72 is prevented by the non-return valves 79 and 83.

In order to release the spring 72, non-return valve 83 may be pushedback by hand, by a knob 84, or by remote control as indicated at 85. Theliquid above piston 81 may now rapidly return through conduit 86 intothe reservoir 87 While the released spring 72 will pull by means of rod82 the piston 81 rapidly upwards into its original rest position.

The operation of the device will now be more specifically described withreference to Figs. 1 and 4, exemplifying the device as applied to theclosing of an oil circuit breaker.

In Fig. 4, the oil circuit breaker is generally designated by 90, theterminals of a network by 91, 92. The contact bridge 93 carries themovable contacts 94, 95. The contact bridge is operated by the commandrod 96 held under tension by spring 98 extended between the housing ofthe circuit breaker and a sleeve 97 with which rod 96 is secured to thecontact bridge 93. The stationary contacts are 99, 100, respectively, ofany conventional type. The contacts are provided with the conventionallocking or holding means, schematically indicated at 101, 102, and withthe conventional releasing means which however are not shown here indetail since they do not form any part of this invention and are wellknown in the art.

The spring tensioning bar 12 is provided at its end with a cross pieceto which two catches 106, 107 are pivoted, at 108, 109, respectively.The catches are inwardly drawn, resiliently, by means of a spring 110,their inward motion being stopped by abutments 111, 112 at the piece105.

A truncated cone 115 is provided at the free end of command rod 96 forsubsequent engagement with the catches 106, 107.

As long as the spring 11 is released, the catches 106 and 107 are at adistance from and do not engage the truncated cone 115. In this releasedposition of spring 11, the stroke limiting contact 53 is closed, as Fig.1

illustrates, and the pulse controller is energized in the followingcircuit: Terminal 28line 54switch 53--line 55-line 56-motor 32line57line 58terminal 28.

The pulse controller, if in the form of a periodic switch as exemplifiedin Fig. 1, will intermittently and pulsatingly close and open, overswitch 34, the energizing circuit of coil 22 of the electromagnet, thussupplying the coil with current pulses in the following circuit:Terminal 28line 54-stroke limiting switch 53l-ine 55- line 59coil 22line60switch 34-]ine 61-line 58 terminal 28.

On the other hand, when a pulse generator is employed as pulsecontroller, the pulse generator will intermittently and rhythmicallysupply directly these current pulses to coil 22 over lines 59, 60.

With each arriving current pulse the electromagnet is actuated, theplunger 24 is drawn into the coil and rocks lever 42 about pivot 43against the action of spring 44. This movement advances, through theintermediary of the driving pawl 45, the toothed rack one tooth, orstep, in the direction of the arrow F. A return movement of rack 13 isprevented by the holding pawl 47.

The length of the stroke of the plunger 24 may be adjusted by means ofthe abutments 37, 38, and the adjustment of the set screws 35, 36, sothat the stroke of the plunger corresponds to the pitch of the toothedrack or of the ratchet wheel, the ratio of the length of the leversbeing taken into account.

With each energizing pulse supplied to the coil 22 of the electromagnetfrom or over the pulse controller 30, the toothed rack is advanced onetooth and the spring 11 is gradually tensioned. As the spring 11 isgradually tensioned, step by step, the catches 106, 107 approach and,towards the end of the movement of bar 12, engage the surface of thetruncated cone 115 as shown in Fig. 4, until, at the end of the strokeof bar 12, the catches 106, 107 under the action of spring 110 engagethe truncated cone underneath its base 116, and the circuit breaker isthus ready for being closed by means of the actuating spring 11.

As soon as the tensioning of the spring and also the coupling with thecommand rod 96 of the circuit breaker are completed, and the rack hasreached the end of its stroke, the abutment or stop 52 opens the strokelimiting contact 53 and thus cuts ofli the energy supply to theelectromagnet.

When the circuit breaker is to be closed, the spring 11 will be releasedby any conventional or convenient means, for instance by the levermechanism schematically indicated in Fig. 1.

Through the operation of this lever mechanism, the driving pawl 45 andthe holding pawl 47 will be pivoted, against the tension of theirsprings 46 and 48, and the pawls will be lifted out of engagement withrack 13. The release bar 12, under the action of spring 11, is displacedabruptly in a sense opposite to arrow F and is returned to its startingposition. Through this movement, since the catches 106, 107 hold thecommand rod 96 of the circuit breaker engaged from underneath, thecontact bridge is instantaneously moved upwards and the circuit breakerwill be closed. Thereon, the contact bridge will be held blocked in theclosed position by the conventional means. At the same time noses 116,117 provided at the catches 106, 107 enter between and engage thestationary abutments 118, 119, respectively. The catches are thus spreadfrom each other and release the cone 115 at the end of the closingstroke of contact bridge 93; cone 115 with the command rod 96 andcontact bridge 93, however, being held in this upmost position by theconventional holding means of the contact bridge.

The circuit breaker may subsequently be opened by releasing the blockingmeans of contact bridge 93 as conventional in the art and thus not shownhere.

With the return movement of bar 12, contact 53 closes 6 again, the pulsecontroller is again energized and-supplies energizing pulses to coil 22of the electromagnet. However, the electromagnet and the rocking leverwill work idly until the pawls 45 and 47 have been released forengagement with the rack. Spring 11 will then be tensioned againautomatically. Bar 12 will be displaced and at the end of its movementwill again engage the command rod of the circuit breaker. Should at thetime when the pawls are released the circuit breaker still be closed,the catches 106, 107, released from the abutments 118, 119 at thebeginning of the downward stroke of bar 12, will slidingly engage therod 96 underneath the cone at a distance therebelow sufiicient to allow,subsequently, for an unimpeded opening stroke of the contact bridge ofthe circuit breaker.

In order to provide for sufficient time and allow the rack and thespring to return to their rest position, stroke limiting contact 53 willconveniently be a retarded closing contact.

The air-space above or the stroke of the electromagnet plunger 24 willcorrespond, as already pointed out hereinabove, to the pitch of theteeth of rack 13. On the other hand, the air-space is determinative ofthe power withdrawn from the network for energizing the electromagnet.The device of the invention may be adapted by extremely simple means tothe capacity of the energy source or to the magnitude of the power whichit is intended to withdraw from this source. To this purpose, the part13 which carries the teeth of the rack may be made exchangeable.

In case it is desired to withdraw only a very small amount of energywith each impulse, it will suffice to provide upon the bar 12 a rackwith teeth of a small pitch and adjust the stroke of the plunger of theelectromagnet correspondingly by adjusting the set screws. However, witha source of sufficient power from which energy of great magnitude may bewithdrawn at once without inconvenience and if it is desired to reducethe length of time needed for the tensioning of the spring, a rack ofgreat pitch of the teeth will be secured to the bar 12. The air-spaceand correspondingly the stroke of the plunger 24 will then beproportionally increased by adjustment of the set screws 35, 36.

The velocity with which the spring will be tensioned may also be variedby regulating the frequency of the pulses produced in the pulsecontroller 30, under the condition, of course, that the type of pulsecontroller employed allows of such regulation.

It will readily be understood that the device as. illustrated in Figs. 2and 3 may similarly be connected at or by means of the rods 67, 81 tothe movable equipments of circuit breakers for actuating them by meansof springs 70 and 72 and that the devices may actuate the circuitbreakers by means of expansion springs, Figs. 1 and 3, as well as bycompression springs, Fig. 2.

Figs. 5 to 8 illustrate a further embodiment of the invention where thenecessity of imposing upon the electromagnet 'a definite stroke isadvantageously avoided.

In this embodiment, the electromagnet 21 with its plunger 24- isoperatively connected through a unidirectional wedge-grip clutch to ashaft 131 carried in bearings 132, 133. A second unidirectionalwedge-grip clutch is provided between shaft 131 and a stationary pointof the framework. Each clutch includes a Wheel rim or ring 134, 137,respectively, carried freely revolvable upon a hub 135, 138 secured tothe shaft 131. Each of the clutches further comprise a cam disc 139,143, respectively, secured to the hubs 135, 136, the cam discs beingprovided with cam rises 140, 144. Cam rollers or balls 141, 145, orother elements with releasable wedge action, are urged by springs 142,146 between the cam rises 140, 144 and the inner circumferences of therings 134, 137.

Figs. 5 and 7 show that disc 139 and ring 134 grip each other throughwedging of the cam rollers when ring 134is rotated clockwise relativelyto cam disc 139 or when the cam disc is rotated counter-clockwiserelatively to ring 134 and, conversely, that the grip between both isreleased when ring 134 is rotated couter-clockwise relatively to the camdisc 139 or when the cam disc 139 is rotated clockwise relatively toring 134. Ring 137 and cam disc 143 are operative in the same sense.

Ring 134 carries a rocking lever 148 which by means of link 41 isconnected to the movable core or plunger 24 of the electromagnet. Witheach. power stroke of plunger 24, ring 134 will grip cam disc 139 and,by means of hub 135 will thus advance the shaft one step, the amplitudeof which is indeterminate and will readily adapt itself to theprevailing conditions of the mechanism.

A spring 149 extended between the rocking lever 148 and the framework ofthe apparatus will effect the return stroke of plunger 24. With thisreturn stroke, ring 134 will be rotated counter-clockwise and willrelease the grip on cam disc 139 and thus on shaft 131. Any returnmovement of shaft 131 is prevented through the second clutch device.Ring 137 of this device is held from rotation by a lever 150 of onepiece with it and secured at its free end to a bracket 151. The clutchof this device, Fig. 7, will release its carn disc 1 53 and thus shaft131 with each advance movement, clockwise, of the shaft, will howeverwedge the cam rollers 145 between the cam rises 144 and the innercircumference of ring 137 and will thus block shaft 131 when this shafttends to return, counter-clockwise.

Shaft 131 is operatively connected, by means of intermediary mechanismwith the head 155 of the spring tensioning member, push rod 154, of thespring 152 which is to be tensioned and is thus to be charged as anenergy accumulator with mechanical energy through the periodic drive ofthe electromagnet, as will be described in detail hereinafter.

periodicity or rhythm conformable to the device selected. This pulsecontroller may be of any one of the types hereinabove described withreference to the preceding figures or may be of the specific typeillustrated in Fig. 5 which will now be described.

In this embodiment, the motion of the driving mechanism itself isemployed for periodically supplying and cutting off the energy to thedriving mechanism.

The electric energy is supplied to the coil 22 of the electromagnet froman electric network 160. The intermittent command apparatus is generallydesignated by 161. In the example illustrated, a contact 172 is providedupon the shaft 131 rotating therewith. Contact 172 is connected throughline 162 with one terminal of the network 161) and may slide upon aring-shaped contact rail 173 and finally reach, in the tensionedposition of the spring, a contact 176 separated from rail 173 through anair gap 163. Rail 173 is connected at its one terminal A through line164 to the one terminal of coil 22, the other terminal of the coilleading over the command apparatus 161 and line 165 to the otherterminal of the network 160.

The command apparatus 161 includes a tumbler switch 177 pivotal aboutpin 181 and about the axis of a pin 182 tiltable with it and through aslot of which it may slide. Arm 183 of the tumbler switch carries thecontact 179 opposite a stationary contact 178 for cooperation therewith.The tumbler contact is operated by a finger 180 secured to the rockinglever 148 so that at the end of each downward or power stroke of theplunger 24, the tumbler contact is tilted counter-clockwise about pin181 and thus opens the contacts 178, 179

magnet coil 22.

Spring 149 now draws back the rocking lever 148 and plunger 24 returnsto its upward position. At the end of this return or upward stroke ofthe plunger, finger 188 will now push and pivot the tumbler switchclock- 'WlSe about pin 181 and will thus close the contacts 178, 179, sothat again an energizing pulse will be supplied to the coil of theelectromagnet. This cycle is rhythmically repeated.

In order to ensure a precise and complete opening and closing motion ofthe tumbler switch, the lever of this switch is in form of a togglelever, comprising the toggle arms 183, 184 articulated at 185. Togglearm 184 is slidable within the swivel pin 182, and the toggle sys tem isurged into the broken positions by means of a spring 186, carried uponarm 184 and tensioned between swivel pin 182 and the head of arm 184 atthe joint 185.

The device operates as follows:

The device as shown in Fig. 5 is in the position where the spring 152,which is to actuate the mobile equipment of a circuit breaker, istensioned and the device thus is ready to close the circuit breaker.This may be effected, for instance, by means of shaft 131 which may becoupled to the command shaft 191 of a circuit breaker by anyconventional or convenient means. These means, since they do not formpart of the invention, are not described here in detail but are merelydiagrammatically indicated in Fig. 8. Shaft 131 is shown as providedwith a cam finger 187 which when shaft 131 is turned clockwise willstrike against a earn 188 on the command shaft 191 of the movable lever189 of a circuit breaker 190 and will thus pivot the lever into theclosed position.

In the position of Fig. 5, the crank arm and the link 156 are in thedead point or stretched position of the toggle joint they form, thusboth members are in the direction of the axis O-X, the extension of theaxis of spring 152. Contact 172 is upon contact 176, as illustrated, andthe current is interrupted. The command 161 is at rest.

In order to close the circuit breaker, a push button contact 175,connecting contact 176 to line 164, is closed. The energizing circuit ofmagnet coil 22 is thus closed in the following circuit: Network line162contact 172-contact 176push button contact 175line 164- coil22contacts 178, 179-line -network160.

The plunger 24 of the electromagnet is pulled downwards and, by means oflink 41 and rocking lever 148, rocks ring 134 and advances it one step,clockwise. 'Clutch 139 grips hub 135 and turns shaft 131, thus movingthecrank am 155 out of the dead point position. Spring 152 is abruptlyreleased, unimpeded by the clutches 139, 143 anddrives the crank armclockwise and with it the shaft 131 one step. Shaft 131, by means. ofthe cam mechanism 187, 188 or by any other convenient or conventionalmeans will actuate the command shaft 191 and close the circuit breaker189, 190.

Let us assume, the deflection of the crank arm when the spring isreleased corresponds to an angle 0:, inside of which the deflection ofthe circuit breaker arm for closing the circuit breaker lies. As soon asthe crank arm 155 I contact 172 will also have been deflected about thisangle and will have reached the nearly circular contact rail 173. Thecircuit of the pulse controller is now closed through line 162contact172-contact rail 173 and the supply of energy pulses to the magnet coilis started. With each pulse, ring 134 is an angular distancecorresponding to the stroke of the plunger of the electromagnet, and camdisc 139 will be advanced one step, gripped by the cam rollers 141 nowwedged between the cam rises 140 and ring 134. With the advance of camdisc 139, shaft 131 will also be advanced.

This pulsating advance is continued until the crank arm 155 hasdescribed an angle of 360a and has returned to the dead point positionO-X. Before this point is reached, during the course corresponding tothe angle [3, the spring 152 is re-tensioned. With the last pulseexerted by the electromagnet and before the crank arm reaches the deadpoint, contact 172 leaves the contact 173 at the point A and comes torest upon the contact 176'.

The circuit of the pulse controller thus is opened, the electromagnetstops operating and the crank arm remains in the position O-X.

Since, after the last pulse, plunger 24, drawn upwards by spring 149 androcking lever 148, closes the contacts 178, 179, the command apparatusis again ready for the next closing operation of the circuit breaker,which, as has just been described, is effected by pressing thepushbut'ton contact 175.

During the tensioning phase of operation and the return or upward strokeof the plunger, the stationary ring 137 and its clutch 143, 144, 145will, as described hereinabove, prevent crank arm 155 with shaft 131from turning, under the bias of spring 149, counter-clockwise.

Should the network 78 which energizes the coil of the electromagnet be adirect current network, contacts 178, 179 may be shunted by acapacitance 166, and the coil 22 by a resistor 167.

Obviously numerous variations and modifications of the instant inventionare possible in the light of the above teachings. Accordingly it is tobe understood that with-in the scope of the appended claims theinvention may be practiced otherwise than as specifically describedherein.

I claim:

1. In combination with a circuit breaker of the type closed by a strongspring to assure quick closing, a spring tensioning member connected tosaid spring, an electromagnet, motion transmitting mechanism foroperating said spring tensioning member in response to the verticalreciprocating movement of the core of said electromagnet, a source ofelectrical energy, supply lines electrically connecting saidelectromagnet to said source of electric energy, a pulse controllerinterposed in said supply lines and responsive to the vertical movementof said core for controlling the flow of energy from said source to saidelectromagnet in pulses at a predetermined rate thereby to actuate saidmotion transmitting mechanism, operate said spring tensioning member andtension said spring at said predetermined rate of flow of the drivingenergy supplied to said spring actuating member, said motiontransmitting mechanism including a spring tensioned rocking lever linkedto said movable core, a unidirectionally operative coupling gear forwedge-grip operatively connecting said rocking lever to said springtensioning member, said coupling gear including a shaft operativelyconnected to said spring tensioning member, said unidirectionallyoperative coupling gear comprising a pair of clutches, each clutchincluding a cam disc mounted upon said shaft and having cam rises andcam rollers for cooperation therewith, a ring being disposedperipherally about each cam disc, coaxially therewith and with theshaft, one of said rings being rigidly joined to said rocking lever tobe rockable therewith, the other ring being stationary; said cam rollersbeing disposed between said cam rises and the inner circumferences ofsaid n'ngs, thereby to wedge by the one clutch said rockable ring to thecam disc appertaining thereto and to couple said rockable ring to saidshaft upon a power stroke of the movable member and to advance theshaft, the grip of the other clutch upon the stationary ring beingreleased during this advance motion of the shaft, whilst, during thereturn stroke of the movable member, the ring of the rocking lever isreleased by its clutch, the shaft, however, being prevented from anyreturn movement, under the tension of the spring, through the otherclutch Wedging its cam disc to the stationary ring.

2. A device as set forth in claim 1 including a crank arm mounted uponsaid shaft, a connecting rod connecting said crank arm to said springtensioning member, said crank arm and said connecting rod constituting atoggle joint disposed with relation to said spring tensioning member soas to allow full revolution of the shaft with passage through thestretched position of the joint, the spring suddenly being releasedunder its tension in a first part of the revolution through collapse ofthe joint in the sense and towards the side of the advance motion of theshaft, the spring being tensioned through continued rotation of theshaft in the same sense until, on further movement in the same sense,the joint approaches from the other side its stretched position;detensioning of the spring and collapsing of the joint during this phaseof operation being prevented through the cooperation of the clutches.

3. A spring tensioning device, particularly for the actuation of circuitbreakers, including a spring, a tensioning member connected to saidspring, an electromagnet, motion transmitting mechanism including aspring tensioned rocking lever linked to the movable core of theelectromagnet, and intermediary mechanism operatively connecting saidrocking lever to said spring tensioning member; supply lineselectrically connecting said elec tronmgnet to a source of electricenergy, a pulse controller associated with said supply lines, said pulsecontroller including switching means operatively connected to saidrocking lever and connected to said supply lines, thereby on rockingmotion of the rocking lever, alternatingly to connect and disconnectsaid electromagnet to and from the source of energy and thus to operatesaid spring tensioning member and tension the spring at a predeterminedpulsating flow rate of the driving energy supplied to the springtensioning member.

References Cited in the file of this patent UNITED STATES PATENTS Re.22,853 Crabbs Mar. 18, 1947 10,128 Clark Oct. 18, 1853 2,470,675 AllanMay 17, 1949 2,646,660 Schild July 28, 1953 2,674,345 Favre Apr. 6, 1954

